The present invention is directed to the art of producing an oven stable food paste, such as a filling or topping for use in baked products. The bake products are fruit filled cereal bars, muffins, and cakes. Also, such products are pastries and cookies. More particularly the invention is a cold process to make high solids, pectin containing fruit paste which can be stored for long periods of time, can be pumped onto or into dough structures, and then baked into finished products.
Oven or bake stable fruit paste, such as fillings or toppings, is normally made by a method involving heating and cooling steps with the disadvantages associated with such hot food processing technology. As a substantial advance in this technology, a cold process was developed and is now widely used to produce a bake stable fruit paste. This cold process is described in Rock U.S. Pat. No. 5,932,270, incorporated by reference herein as background information since much of this prior technology is used to practice the present invention. This prior cold processing method and the present method both utilize a rapid, high power blender known as a Tri-Blender and described in Zimmerly U.S. Pat. No. 3,606,270. This patent is incorporated by reference herein to show generally the type of high speed blender used in practicing the present invention.
The cold processing method as disclosed in Rock U.S. Pat. No. 5,932,270 employs cold water swelling starch as the stabilizer for the fruit paste. This prior cold processing method can not be used with pectin containing fillings, even though pectin stabilized filings can produce a better flavor and better customer acceptance and has a less pasty consistency and good appearance. Consequently, some manufacturers of baked dough products still prefer to use a paste made by the hot pectin process. This pectin process does not have the cost and time advantages of the cold process obtained by the prior art starch stabilizing method. But, it does have the advantages of pectin. Manufacturers of pectin stabilized high solid fruit paste normally use a hot processing technique because of the disadvantage of attempts to use a cold process for pectin stabilized fruit paste. Such hot pectin techniques produce a product with a total solids in excess of 60% and are commonly used in the food industry.
Pectin must be solubilized before being used as a stabilizer. Solubilization involves the dispersing and dissolving of pectin molecules in water. Solubilization involves dispersing pectin by strong agitation in order to separate the pectin particles while avoiding formation of agglomerated lumps. When the pectin particles are separated, and subsequently the pectin molecules themselves individualize, they swell due to exposure to water. By agitation in a large amount of water and with application of heat to facilitate solubilization, the pectin is activated for use in a fruit paste. Solubilization of pectin is normally done by agitation in a high amount of water at high temperature. Pectin solubilization must be addressed in either a hot process or the novel new cold process. Solubilization is required. In the past it was done in a low solids matrix and then used in a hot processing technology. Hot process in the food industry means a substantial amount of heat input and then cooling by heat withdrawal.
To produce a pectin stabilized paste, the pectin is initially solubilized. This is accomplished in a mixture having a total solid content substantially less than the final solids content for the paste. As mentioned, solubilization normally involves heating a low solids content liquid phase to a specific temperature and then adding powdered pectin under high agitation. The pectin is allowed to fully solubilize in a specific period of time while the pectin is exposed to a high percentage of water. It has been the conventional wisdom that pectin can be solubilized or activated only in a liquid phase having a solids content of less than 30% and at a high temperature, such as 160xc2x0 to 180xc2x0 F. This was because of difficulty in fully solubilizing and activating the pectin at a solids level greater than 30%. In addition, it is common practice to use high shear mixing of the pectin to fully disperse and dissolve the pectin into the low solids content liquid phase. High shear tends to avoid the formation of fish eyes or pectin lumps that can be detrimental to achieving the full functionality of the pectin. The water volume required to achieve efficient solubilization of the pectin exceeds the water allowed for in a high solids filling. This additional water must be removed either by heat or by a combination of heat and vacuum. Both of these processes add to the processing time and equipment necessary to produce a bake stable fruit paste using the normal hot process. It is further necessary to hold the high water liquid phase containing the solubilized pectin at a constant minimum temperature of about 160-170xc2x0 F. until the pectin is to be combined with a high solids liquid phase to produce the final product. The high solids liquid phase must be heated to a temperature greater than 160xc2x0 F. to mix with the pectin phase. This is necessary to avoid pregellation of the pectin as the low solids pectin solution is added to a high solids component or phase to make the paste. Maintaining this temperature, as required in the hot process, is also important because acid and/or calcium source for low methoxyl pectin fillings is added as a final step to the pectin stabilized filling. It is a common industry practice to make and add a 50% acid stock solution for pectin stabilized pastes. The calcium source for low methoxyl pectin fillings is dispersed separately in a small amount of water prior to adding to the batch. If the temperature of the batch is allowed to fall below a certain critical gelling temperature prior to the addition of the acid and/or calcium to gel the pectin, the pectin will prematurely gel and negatively impact the final targeted bake stability of the paste. This critical gelling temperature is dependent upon several factors, including the total solids content, the pH, the pectin concentration and the pectin reactivity, especially when the pectin is a low methoxyl pectin. Once the targeted final solids content for the paste has been reached, the paste must then be cooled mechanically to the fill temperature.
The hot process requires introduction of heat in the form of steam of electricity and, thus, requires substantial input of energy. In a high solids type paste, heating of the product during the processing requires a substantial amount of time and special equipment. Thus, time necessary to produce the product, such as a fruit paste, is increased when using the hot process, which process has heretofore been used when pectin is the stabilizer of choice. In addition, some food products, such as fruit paste used in bakery products, lose a portion of the fresh taste when exposed to a long period of heat before use in a baking operation. The paste takes on the characteristics of cooked fruit. This is commercially detrimental when a natural, fresh filling attribute is required for the end product. Fruit paste, and other food products, which have added flavoring and color pigmentation to enhance the taste, aroma and appearance have these characteristics diminished by using the hot process heretofore required to obtain the advantages of a pectin stabilized product. In most instances, fruit paste and other similar products are stored and then shipped to a bakery for subsequent use. Consequently, the hot paste must be cooled prior to packing. This added process operation increases the process time and increases the equipment required for producing a bake stable fruit paste. When the paste is cooled after it is made by a hot process and prior to packing, added time and equipment are required. This expense is not justified by an enhanced characteristic of a paste using pectin.
In addition to the energy needed to make the paste with a pectin stabilizer, high solids pectin paste also requires heat to solubilize the pectin. In the past, pectin was solubilized in excess water. Consequently, to remove the excess water required for pectin solubilization greatly increases the process time and the cost of producing pectin paste. The heating and cooling requirement for a hot process line, including solubilization of the pectin, creates a significant production bottleneck from the standpoint of throughput. The equipment necessary to handle the extremely high viscosities caused by a hot process is expensive and slow. These high viscosities typically developed when heating and cooling the filling during processing thus making handling and pumping more complicated. Consequently, such paste must be deposited into containers or drums at a temperature higher than those which are desirable for long term shelf life and flavor maintenance. Otherwise the paste is too thick to pump. In many instances, the paste, once packaged, must also be placed in a refrigerator to accelerate the cooling of the paste to room temperature. These are some of the many disadvantages associated with a hot process which is used to obtain the advantage of a pectin gel system for a paste or filling. A lot of the disadvantages can be overcome by using a cold process technology.
There currently exist a limited number of cold processes which results in a paste that can withstand the oven temperatures encountered during a baking operation; however, a cold process technology using pectin has not yet been developed. Exposure of the bakery filling to such high temperatures as seen in the baking operation negatively affect the desired functionality of the final food product. Oven or bake stability of the paste is primarily related to the type of stabilizing system and to a lesser extent the overall solids content of the paste. One prior cold processing method involves a stabilizer system using alginate. A bake stable paste can be produced using this process; however, there are distinct disadvantages when using alginates as explained in Rock U.S. Pat. No. 5,932,702. This patent discloses a recently developed cold process technology that employs granular instant starches in combination with microcrystalline cellulose as the stabilizer system. These two cold process technologies, one using alginates and one using granular instant starches, do not create a product with the organoleptic advantages associated with fillings stabilized with pectin. In summary, the presently used cold process technologies for making a bake stable food paste can not make a paste with the characteristics of a pectin stabilized product. The use of alginates is predicated upon the slow release of calcium within the stabilizing system for form a bake stable gel. Granular instant starch technology in Rock U.S. Pat. No.5,932,270 relies upon cold hydration of the starches in a water starved system to impart bake stability to the end product. Both of these systems are limited in the sense that both stabilizing systems retard or mask flavors in the filling. The alginate process can have an inherent off-flavor derived primarily from its natural source, which in addition to the gel that forms, negatively impacts flavor and flavor release characteristics of the paste. As to the granular instant starch technology, there is also a negative effect on the flavor profile simply as a result of the high starch load required to achieve the necessary bake performance. Furthermore, granular starch technology imparts a pasty or heavy mouth feel not typically associated with natural fruit or fruit derived products. Consequently, the cold process technology with all its tremendous economic advantages is seriously limited when applied to the high solids oven stable or bake stable fruit paste of the type used as a filling or topping on baked goods. These processes have not heretofore been adapted for adoption of the advantages associated with pectin stabilized fruit products.
There exists a need for a cold process technology to produce a pectin based high solids oven stable or bake stable fruit paste, which process avoids the need for traditional pectin solubilization techniques common to industrial hot process methods of manufacturing such high solids pectin bakery filling. This prior solubilization technique of using high water amounts and the need to maintain temperature above a gelling temperature of the reacted pectin was believed to prevent use of pectin in a cold process.
The present invention relates to the composition of a paste, which composition is accomplished by a cold process technology. xe2x80x9cPastexe2x80x9d is a general term to mean fillings, toppings, etc. The invention involves the use of high methoxyl and/or low methoxyl pectins, wherein the first type pectin gels as a result of the combination of the proper pH and total solids and the latter type pectin gels primarily as a result of a cross linking reaction with calcium ions. Either one, or both pectins are dispersed into a buffered high solids liquid phase composed of a combination of corn syrup, dry sweetener, and fruit puree. The liquid phase is greater than 30% solids and more specifically is greater than 60% solids. Temperatures of the liquid phase typically range from 110-120xc2x0 F. with mixing times of 5-20 minutes after the pectin is added. This mixing is at high agitation to solubilize the pectin in a high solids phase. A small amount of additional heat may be applied if desired. Such heat would not involve hot processing, since the temperature stays below 130xc2x0 F.
The primary aspect of this invention is a method whereby pectin can be solubilized in a high solids environment at low temperatures to impart the necessary functionality or bake stability to the fruit paste. This invention presents a distinct departure from common accepted industry practices related to the manufacture of high solids, pectin bakery fillings. The invention also involves the use of a dry component. This dry component is ultra rapidly combined with the above discussed liquid phase containing pectin to produce a product which is packed immediately to accomplish the bake stability obtainable by practicing the present invention. The term dry blend composition or dry composition is defined as a component that has low free water. The dry blend composition is dependent upon the type of pectin being used and is used to promote the subsequent formation of the pectin gel once the two phases are rapidly combined and stored. The dry blend composition is a combination of acids and/or different calcium sources dependent upon the type of pectin being used or the bake stability required. The pectin in the liquid phase is gelled after being combined together with the dry phase and not before or during the step of combining the two phases. This rapid blending before pectin gelling provides the bake stability of the ultimate product. This result can be accomplished by a liquid to liquid embodiment like FIGS. 14 and 15 of Rock U.S. Pat. No. 5,932,270. This embodiment will be explained later.
Another aspect of the present invention is combining the acid and/or calcium source material with the pectin containing liquid phase at a temperature far below the gelling temperature of the pectin without formulation of pre-gel. The finished gelled paste possesses a total solids content of 60-85% and more typically 70-80% total solids. In addition, the water activity of the finished paste ranges from 0.50-0.80 or more typically in the range of 0.60-0.70. Typically, the water activity is 0.65-0.70 in the finished product. The novel characteristics of the paste produced in accordance with the invention are identifiable in the end product and result in the advantages of a paste constructed in accordance with the present invention utilizing a cold process technology, but still having the advantages of a pectin gel system. The pH of a finished filling or paste ranges from 3.0-5.0. Typically the pH is 3.2-3.8. In the preferred embodiment, the pH is in the range of 3.2-3.6 for high methoxyl pectin or 3.4 to 4.2 for low methoxyl pectin.
The present invention involves a cold process for making a pectin bake stable fruit paste including a fruit, water, corn syrup, acid, and/or a calcium source with acid buffer salts. The stabilizing system is comprised primarily of high methoxyl pectin, low methoxyl pectin or a combination of high methoxyl and low methoxyl pectin. The high methoxyl pectin can encompass a degree of esterification in the range of 62-72 or higher. The preferred DE is 68. The low methoxyl pectins are defined as pectins that are reactive with calcium ions. Those pectins have a DE range from 10-61. A DE of 38 is preferred in the present invention. Pectins can be derived from sources such as apples, citrus fruits, beets and other sources that meet the above mentioned requirements for DE. Pectin can also be combined with other stabilizers such as alginates, modified food starches, fruit powders such as apple powder, microcrystalline cellulose (MCC), carboxymethyl cellulose (CMC), or combinations thereof. The addition of these supplemental stabilizing components take advantage of synergies and other functionalities not provided by the pectin alone. Stabilizers in addition to pectin can be added either to the liquid phase or dry phase of the cold process. As an aspect of the invention, the pectin in the process have levels in the range of 0.1% to 1.5% by way of the total formulation and more particularly 0.8%-1.2% of the total formulation.
Another aspect of the present invention is the use of acid in combination with the high methoxyl and/or the low methoxyl pectin. These acids may be varied. For instance, some of the acids now used are citric acid, malic acid, adipic acids, acetic acid, glucono delta lactone and phosphoric acid. Citric acid and malic acid are preferred. The temperature of the liquid and the particle size of the acid in the dry form controls the rate at which the pectin reacts or gels when the pectin containing liquid phase is combined with the dry phase. The acid is present in the dry phase. To avoid pre-gellation of the pectin the correct acid is identified and is manipulated to control the rate at which the acid dissolves once the liquid phase and dry phase are combined. The rate of dissolution or solubilization of the dry acid when the phases are combined controls the rate at which the pH drops to gel the pectin. This control of gelling affects the bake stability of the final product. The optimum results are accomplished by controlling the particle size of the dry acid as related to the particle size of the buffer salt. The optimum particle size for the dry acid typically consists of a granulation that ranges from 149-590 microns. More specifically, at least 60% of the particles have a size in the range of 250-500 microns. The particle size that are more coarse tend to unduly delay pectin set times, while particle size that are finer tend to result in a rapid pre-gellation of the pectin. Slight modification of the particle size optimizes these two characteristics. Furthermore, this technology is defined as cold process. Temperature of the liquid phase typically ranges from 110xc2x0 F. to 130xc2x0 F. Prior to blending of the liquid and xe2x80x9cdryxe2x80x9d phrase, the liquid phase can be cooled to a temperature of 90xc2x0 F. to 110xc2x0 F. If the temperature of the liquids is too hot, 160xc2x0 F. to 180xc2x0 F., the acid will solubilize too rapidly causing the solubilized pectin to react and pre gel prior to depositing into the package.
In still a further aspect of the invention, the calcium ions are released from a calcium source located in the dry phase to gel the pectin when the pectin is a low methoxyl. Various calcium sources are available, such as calcium citrate, calcium lactate, tricalcium phosphate, dicalcium phosphate and calcium sulfate. Calcium citrate, tricalcium phosphate and dicalcium phosphate are preferred in practicing the invention. The rate of calcium ions released into the matrix as the liquid and dry phases are being blended, determines the rate at which the pectin reacts or gels. The pectin in the liquid phase is combined with the calcium source present in the dry phase. The calcium release rate is affected by the solubility and solubility rate of the individual calcium source as well as the rate at which the accompanying dry acids in the dry phase are solubilized by water from the liquid phase. The rate of solubilization of the dry acid is controlled by the granular size of the acid particles and the temperature of the combined liquid and dry phase. It is preferred to avoid pre-gellation of the low methoxyl pectin by identifying the optimum calcium source as well as the optimal acid to obtain a slow uniform release of calcium. This allows delayed gelling to obtain a paste with the required bake stability. Adjustment of the release rate of the calcium ions is known in the art and is used with hot process technology as well as being used in the cold process of the present invention.
In accordance with yet another aspect of the invention, buffer salt is used to facilitate pectin solubilization in the liquid phase. The salt prevents acid from the fruit from gelling the pectin as it is being solubilized in the liquid phase. Such salt is also used in the dry phase in combination with the dry acid to control the rate of acid and calcium release once the two phases are combined for blending. To control the rate of pectin gellation, once the liquid and dry phases are combined, the buffer salt be added to the dry phase as small particles. Some appropriate buffer salts are sodium citrate, potassium citrate and sodium phosphate. Other salts could be used. Buffer salt in the liquid phase is used primarily to raise the pH sufficiently to promote pectin solubilization without gelling. This is especially important when high methoxyl pectin is used since the solids content exceeds 55% or more. During solubilization a low pH with high solids could cause pre-gelling to defeat the cold process. Generally it is preferred that the buffer salt be present in the dry phase to control the rate at which the pH is lowered once the dry and liquid phases are combined. The buffer salt is manipulated to solubilize at a slower, equal, or faster rate than the acid thereby controlling pectin gellation. Solubilization of acid and salt is determined primarily by particle size, but is also affected by the temperature of the liquids. The key is to slow down the acid release, but not by using coarse particles. In this sense it is preferred that the buffer salt present in the dry phase solublize faster than the dry acid in the dry phase. This relationship between the conversion of the acid and salt to control the pH of the matrix after it has been mixed for blending, can be accomplished by adjusting the particle size distribution of the acid in relation to the particle size distribution of the buffer salt or visa versa. In this manner, upon introduction of water from the liquid phase, the buffer salt always solublizes faster than the dry acid in the dry phase. The buffer salt controls the rate at which the pH of the combined liquid and dry phases drop as a result of acid solubilization and indirectly the rate at which the calcium is released into the surrounding matrix once the two phases are combined. This action prevents pectin pre-gelation by moderating both the drop in pH and indirectly the rate of calcium release. Thus an ordered pectin network is formed resulting in a fruit paste with the necessary bake stability. The optimum particle size for the buffer salt in the dry phase consists of particles in the range of 44-590 microns. More specifically, 90% of the particles of the buffer salt range from 44 microns to 149 microns. The particle size distribution that are more coarse tend to result in pre-gelation of the pectin while a finer particle size distribution tends to delay pectin gelation. The large particles can not solubilize fast enough to counteract solubilization of the acid. With the finer particle sizes, the buffer salt is solubilized faster to delay drop in pH and thus slow down the pectin gellation to assure that it does not gel until after the two phases are mixed together and pumped into a package or storage container.
A paste formulated in accordance with the present invention and made by a cold process technology has minimal initial process viscosity when the liquid and dry phases are combined and rapidly blended. Consequently, the formulation is easily pumped to the packing station. At the packing station, the paste rapidly sets to a gel. The salt and acid is adjusted so gelling takes place in the storage container. This requires at least 1-2 minutes. In practice the blending is done in less than 60 seconds and preferably in the range of 5-30 seconds. Thus, gelling happens later and after the paste has been constituted.
The pectin in the paste is cold solubilized in the liquid phase of the process. In this phase, the total solids is greater than 30% and more typically greater than 60%. In the past, solubilization of the pectin was accomplished in a liquid having less than 30% solids. The phase had to be heated. In the present invention, the solubilization of the pectin is in a high solids liquid phase and is not heated. This procedure provides the unique characteristics obtained by the present invention when using cold process technology. The present invention makes a paste that withstands 400xc2x0 F. for 10 minutes with less than 10% spread, and preferably with less than 7% spread. This property was heretofore obtained only by hot process technology, especially when used for a variety of pH based compositions having a high solid content. These are the properties of most bake stable fruit paste used in bake products filled by or covered with a fruit paste. The paste has a minimal process viscosity after it has been blended. Thus, the paste can be easily pumped to the packing station.
In accordance with the invention, there is provided a cold process method for forming a pumpable, oven stable, pectin based fruit paste. The term xe2x80x9cpastexe2x80x9d means filling, toppings, etc. This method comprises providing an unheated liquid component or phase containing pectin and a food ingredient. The cold liquid component has a temperature of less than 130xc2x0 F. and a solid content of over 55%. The temperature is preferably in the range of 110-120xc2x0 F. The pectin is solubilized in the cold liquid component. Buffer salt prevents gelling. There is also provided a low free water component or phase referred to as a xe2x80x9cdryxe2x80x9d phase. The dry phase or component contains a gelling agent for the solubilized pectin, granulated dry acid and granulated buffer salt. The buffer salt controls the rate at which the pH is lowered. The two phases are rapidly blended while preventing the gelling of the pectin to form a blended, low viscosity ungelled formulation. This low viscosity formulation is transported to a storage container where it is gelled into a bake stable spread for subsequent use in producing a baked fruit product. The acid and buffer salt are solubilized by water in the liquid phase to delay gelling of the pectin for a time necessary to blend and pump the formulation into a storage container. In the preferred embodiment, the blending is by a high speed mechanical blender forcing the mixed liquid and dry phases to the storage area in less than 60 seconds. In the preferred implementation of the invention, blending time is in the general range of 5-30 seconds. This produces the bake stable product because it is mixed before it gels. Although a high speed mechanical blender such as disclosed in Zimmerly U.S. Pat. No. 3,606,270 is preferred, the invention can be practiced using other mixing devices, such as a static mixer as shown in FIG. 15 of Rock U.S. Pat. No. 5,932,270. This patent is incorporated by reference herein. The static mixer is used for the liquid to liquid implementation of the invention.
In accordance with the invention, when the solubilized pectin is a low methoxyl pectin, the gelling agent is a calcium source having a release controlled by the dry buffer salt and dry acid. When the pectin is a high methoxyl pectin, the gelling agent is acid in combination with the high solids content of the mixed liquid and dry phases. Again, the buffer salt controls the rate of pH decrease caused by solubilization of the dry acid during the blending operation. In either instance, the gelling of the pectin is delayed until the blending or mixing has been accomplished to fix the structure of the paste. The low viscous, ungelled formulation is pumped into the packing or storage container for subsequent gelling. The bake stability is accomplished by the rapid blending before the onset of gelling.
In the preferred aspect of the invention, the food ingredient is a fruit puree. The temperature of the liquid component is maintained in the general range of 110-120xc2x0 F. Basically, the liquid phase is not heated. The solids content of this phase is in the general range of 60%-75%. The dry acid in the low free water component or dry phase has a particle size in the general range of 149-590 microns. The buffer salt in this same dry phase has a particle size in the general range of 44-590 microns. The particle size is adjusted to control the rate of change of the pH during the blending or mixing operation. This delays gelling until the internal structure is finalized.
In accordance with another aspect of the invention, an additional stabilizer such as cold water swelling starch, is added to the formulation, preferably in the dry phase.
In accordance with another aspect of the invention, additional stabilizers, such as microcrystalline cellulose, carboxyl methy cellulose or apple powder is added to the formulation, preferably in the liquid phase.
In accordance with another aspect of the invention, there is provided a bake stable food paste with a total range of 60%-75%, a water activity in the general range of 0.50-0.80 and pH in the general range of 3.0-5.0. This paste contains pectin and is gelled after rapid mixing of the constituents of the paste in a time less than 60 seconds while the paste is subjected to a temperature not exceeding 130xc2x0 F. Preferably, the temperature of the paste does not exceed 120xc2x0 F. and is preferably in the general range of 110-120xc2x0 F. during the cold processing.
The primary object of the present invention is the provision of a cold process method for forming a pumpable oven stable pectin based food paste.
Another object of the present invention is the provision of a cold process method, as defined above, which cold process method utilizes two phases, one of which includes a pectin and the other includes a pectin gelling agent. These two phases are blended together in a time less than 60 seconds to produce a low viscous, non gelled formulation that is pumped into a storage or packing container for subsequent gelling. The structure is established before subsequent gelling of the pectin.
Yet a further object of the present invention is the provision of a cold process method, as defined above, which cold process method allows the production of a bake stable food paste by a process that is not heated beyond 130xc2x0 F., but has a low viscosity allowing efficient pumping through the equipment performing the method.
Still a further object of the present invention is the provision of a cold process method, as defined above, which cold process method allows the use of a pectin stabilizing system without requiring heat and cooling operations.
Yet another object of the present invention is the provision of a bake stable, pectin food paste that is processed by cold process method.
These and other objects and advantages will become apparent from the following description taken together with the accompanying drawings.